Road grader



ns-* 1929 R A. EDWARDS 1,723,019

ROAD GRADER Filed Aug. 20, 1927 i 2 Sheets-Sheet 1 Pe/Q j/h ara s )7 1,3 fly/ame J UNITED STATES PATENT OFFHCE.

REID A. EDWARDS, OF ALBERT LEA, MINEEEOTA, ASSTIGHOP. TO C. D. EDWARDS MAN- UFACTURING CO., OF ALBERT LEA, IVIINNESOTA, A CORPORATION OF MINI'lE-SOTA.

ROAD GBADER.

Application filed August 20, 1927. Serial No. 214,375.

My invention relates to road graders and similar machines, and more particularly to operating and counterbalancing mechanism for the road-working tool thereof, and has for its object to improve the same, as will hereinafter appear.

To the above end, generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a side elevation of a road grader having the invention embodied therein, with some parts broken away and sectioned;

Fig. 2 is a fragmentary plan view of the same;

Fig. 3 is a transverse vertical section taken on the line 33 of Fig. 1, on an enlarged scale; and

Fig. 4 is a detail View with some parts sectioned on the line 4-4 of Fig. 3.

The numeral 5 indicates as an entirety a standard commercial road grader with the exception of its two rearwardly diverging longitudinally extended I-beams 6, which constitute a. part of the frame of the grader, and the draft assembly. This draft assembly includes a pair of rearwardly diverging longitudinally extended drawbars 7, the rear ends of which are rigidly connected by a crosstie bar 8, circle assembly 9 mounted on said drawbars, moldboard 10 which extends transversely of and under the beams 6 and is carried by a pair of diametrically opposite arms 11 rigidly secured to said circle assembly. The forward ends of the drawbars 7 are attached by a universal joint to the road grader 5 directly over the front axle thereof and which joint permits the customary vertical and horizontal swinging movements of the draft assembly as well as angular tilting movement thereof transversely of the grader.

Referring now in detail to the invention, which includes a pair of longitudinally extended shafts 12 which overlie the beams 6 and have the same divergence as said beams. as shown in Fig. 2, the front end portions of the shafts 12 are journaled in bearings 13 on the beams 6 and their rear end portions are journaled in gear cases 14 mounted on said frame bars. The shafts 12' are independently rotated by large hand wheels 15 having short shafts journaled in the gear cases 14: and equipped with worms 16 which mesh with worm gears 17 keyed to said shafts. The hand wheels 15 are arranged to rotate 111 vertical planes parallel to the respective shafts 12.

Keyed to the shafts 12, forward of the bearings 13, is a pair of reversely and outwardly extended arms 18 arranged to swing in the arcs of circles transversely of the grader, and, as shown, at right angles to the respective beams 6. Hangers 19 hold the draft assembly suspended from the swinging arms 18. These hangers 19 are in the form of yokes which straddle the outer end portions of the arms 18 and have their legs at their lower ends pivoted at 20 to the crosstie bar 8 to permit swinging movements of said hangers transversely of the grader. Universal joints 21 connect the arms 18 to the legs of the hangers 19. It will be noted that the hangers 19, above the swinging arms 18, are curved upwardly and outwardly to afford clearance for said swinging arms and permit the hangers 19 to move inward into substan tially vertical alignment with the respective shafts 12. A

A long, heavy pair of equalizing springs 22 extend longitudinally of the grader between the beams 6 and have their rear ends connected to the swinging arms by cables 23, as shown in the form of chains. The forward ends of the equalizing springs 22 are anchored by long nut-equipped eye-bolts 24: to a crosstie bar connecting the beams 6. Oh-

viously, by adjusting the nuts on the eye-bolts 24-, said eye-bolts may. be moved endwise to vary the tension of the equalizing spring The intermediate portions of the cables 23 run over a pair of upper guide sheaves 26 and a lower pair of guide sheaves 27. The upper guide sheaves 26 are journaled to and between a pair of transverse laterally spaced angle bars 28 rigidly secured to the beams 6, and the lower guide sheaves 27 are journaled in bearing brackets 29 on the under side of said angle bars. The upper guide sheaves 26 hold the end portions of the cables 23, which are attached to the swinging arms 18, reversely and outwardly extended transversely of the grader and the lower guide sheaves 29 hold the end portions of said cables, which are attached to the counter-balancing springs 22, extended longitudinally of the grader.

The swinging arms 18 are provided with equalizing cams 30 having channelled peripheries which extend longitudinally of said arms and in which the respective portions of the cables 23 lie. It will be noted that the equalizing cams 30 are cast integral with the swinging arms 18, but, of course, may be otherwise constructed. The action of the equalizing cams 30 is such as to compensate for-the varying tension of the counter-balancing spring 22 so that the action 'of said spring on the moldboard 10 is substantially always the same in the different positions of said moldboard,

Obviously, by operating one of the hand wheels 15, the respective end of the moldboard 10 will be raised or lowered through the connections from said hand wheel to the draft assembly heretofore described. As previously stated, and shown in Fig. 2, thetwo beams 6 are in rearwardly diverging relation and the swinging arms 18 are set at right angles to the respective beams 6, and hence the end portions of the cables 23 between the upper guide sheaves 26 and swinging arms 18 are held atslight angles through channel peripheries of said cams for the reason that the upper guide sheaves 26 are aligned right angles to the longitudinal center of the rader;

In graders having parallel frame beams,

he shafts 12 will extend parallel to each other instead of in diverging relation, as

shown in Fig. 2, and hence the swinging arms 18 will be in true alignment with the upper guide sheaves 26. The arrangement and spacing of the lower guide sheaves 2? is such as to hold the counter-balancing springs 22 and the connected end portions of the cables 23 parallel to each other and with the longitudinal center of the grader. The tension of the counter-balancing springs 22 is such that the we' it of the draftassembly and the moldboard 10 is substantially balanced so that very little power is required to lift the same. Howeuer, there is sufficient weight to hold the moldboard 10 to its work.

By e x t e n d in g the counter-balancing springs 22 longitudinally of the machine and the swinging arms 18 transversely thereof, it is possible to use counter-balancing springs of the proper length to perform their function and at the same time keep the mechanism within comparatively compact space. and also permits the use of simple and highly ef ficient operating mechanism for raising and lowering the moldboard 10. The advantage of using long counter-balancing springs 22 is well known in that the tension thereof will not vary greatly during the raising and lowering of the moldboard 10.

W hat I claim is:

1. A machine of the kind described having 2. A machine of the hind described having a frame, a road-working tool extending transversely under the frame, and a draft assembly for said tool arranged to permit angular raising or lowering movements thereof, in combination with a pair of lifting air as mounted on the frame for swinging movement transversely thereof and power means for int-.ependentl operating the same, of hangers supporting the draft assembly from said arms, a pair or counter-balancing springs anchored to the frame and extending longitudinally thereof, said springs being niaterially longer than the transverse width of the frame, single flexible connections from the lifting arms to the counterbalancing springs, and guide sheaves for changing the direct-ion of the end portions of the flexible connections.

3. The structure defined in claim 2 in which the lifting arms have equalizing cams over which the connections extend.

4. A machine of he kind described having 1 frame, a road-working tool extending transversely under the machine, and a draft assembly for said tool arranged to permit angular r ing or lowering movements there f, in combination with a pair of shafts e1:- tending lon gitu-dinally of the frame and power means for independently rotating the same, of a pair of lifting arms on the sha arranged to swi: transi sely of the f a pair of hangers supporting the draft as sembly from the lifting arms, pair of counter-balancing springs anchored to the frame and extending longitudinally thereof, cable connections from the lifting arms to the counter-balancing springs, said a having equalizing cams over which the cables extend, and guide sheaves on the frame over which the intermediate portions of the cables extend and hold the end portions of the cables that are attached to the swinging arms reversely extender transversely of the frame and with the end poi cions thereof that are attached to the counter-balancing springs extended longitudinally the frame.

In testimony whereof I affix my signature.

nun) A. EDWARDS. 

